Problems of convergence. Soft stoy or not?
Posted: 13 Sep 2018, 18:06
I'm modeling a 4-level steel frame building in Seismostruct for a pushover analysis. I am having problems of convergence and I have followed the recommendations that the program gives me, the message that appears to me when stopping the analysis is this: "The structural model can not withstand the defined loading" ... I have verified loads and structural properties of the elements , as well as the connection of the elements through an analysis of eigenvalues.
What I have managed to verify in the analysis log is that all the columns of the first level 1 come to meet the criteria of yield in only ONE of its extremes, the extreme (A). This criteria performance of yield has been defined by the user based on chord rotation. I can also mention that the last result that the program shows me is the failure of two columns of the first level (the failure criterion was also defined by user)
I understand that to define a failure mechanism for soft story is necessary that BOTH ends of the columns of the first level are in yielding. That is why it is my doubt, whether the building has really collapsed or not and that is why it is not possible to continue the analysis, because in my case only ONE extreme of the the columns reached yielding
Note: to define the performance criteria I used ASCE 41-13
What I have managed to verify in the analysis log is that all the columns of the first level 1 come to meet the criteria of yield in only ONE of its extremes, the extreme (A). This criteria performance of yield has been defined by the user based on chord rotation. I can also mention that the last result that the program shows me is the failure of two columns of the first level (the failure criterion was also defined by user)
I understand that to define a failure mechanism for soft story is necessary that BOTH ends of the columns of the first level are in yielding. That is why it is my doubt, whether the building has really collapsed or not and that is why it is not possible to continue the analysis, because in my case only ONE extreme of the the columns reached yielding
Note: to define the performance criteria I used ASCE 41-13